The Planner and the Gatekeeper

Our brain contains not one but two decision-makers: the Planner (our cortex, which suggests what we should do) and the Gatekeeper (our basal ganglia, which decides whether to do it).

The interaction between the two, depicted below, determines most of human behavior.

A common example

Imagine our cortex (the Planner) decides we should hit the gym. If our basal ganglia (the Gatekeeper) doesn’t like exercising, the cortex’s order doesn’t reach our motor areas, and we do not go to the gym.

What’s the result of liking an outcome but not the action that achieves it? Inaction, and thus, frustration.

The circuitry

The image below depicts a simplified schema of the actual circuitry that you would observe if you dissected a human brain. There is a pathway running from the cortex to the motor areas of our brain. Alongside it, there is an area of our brain called the basal ganglia that can inhibit the pathway, preventing the cortex’s orders from becoming actions.

This circuitry highlights a separation of roles.

The Planner (our cortex) makes plans but does not have direct access to our muscles; therefore, its plans are only suggestions.

Conversely, the Gatekeeper (our basal ganglia) cannot make plans but can block the Planner's suggestions from reaching our motor areas.

For action to occur, our cortex must suggest it, and our basal ganglia must approve it. If either is missing, we do not take that action.

Habit formation

To create new habits, we must ensure that our cortex sends the desired orders and that our basal ganglia allow them to reach our motor areas.

Sadly, most habit formation advice addresses only the former. It involves either making better plans or removing cues from our environment so that we do not come up with bad ideas (such as eating that bag of chips on the table).

However, that is cortex-centric advice that ignores the Gatekeeper. No wonder it is not very effective.

Influencing the Gatekeeper

So, what causes the Gatekeeper to open or close the gate? It's simple: experiential memory. The gate opens when the suggested action is remembered to have brought positive emotions in the past.

We have already seen that the Gatekeeper cannot imagine or plan, only remember. The part of you that can imagine, plan, and consider indirect or long-term consequences is the Planner, not the Gatekeeper. Knowledge, imagination, and planning help generate good suggestions but do not guarantee execution, nor do they prevent bad ideas created by instincts.

Hence, we have two ways to influence the Gatekeeper.

First, we can try to feel emotions. If we feel a strong positive emotion when we think about doing an action, we will be more likely to do it. However, note that emotions are only associated with doing the action count, not emotions associated with the reward. That’s why it’s so hard for many people to go for a workout, even though almost everyone has positive associations with looking fitter. Only how we feel about the action counts, not the outcome. (More precisely, how we feel about the outcome only matters to the extent it creates feelings about the action.)

The second way in which we can influence the Gatekeeper is by creating new experiences that associate a positive emotion with the suggested action.

The key principle

For us to take action, our cortex must both think about it, and our basal ganglia must feel like doing it would feel good.

Hence, habit formation must speak to BOTH the Planner and the Gatekeeper:

• To the Planner: offering better knowledge, more cues for positive actions, fewer for negative ones.

• To the Gatekeeper: providing new experiences and creating new emotional associations.

We must acknowledge that our Planner (our thinking self) cannot just "convince" the Gatekeeper to change. It can only do so indirectly – by planning actions that the GK is already willing to take and having those actions create new emotional associations.

This post is a brief summary of the behavioral model I describe in one of the chapters of my book, "The Control Heuristic." Read the book to learn more about it and behavioral change.